Data going back to before the Civil War confirmed it: 2023 was Earth’s hottest year on record.
Records across the region and state were rivaled and, in some instances, shattered.
At the Tri-Cities Airport, it was the second warmest year on record with information dating to the late 1940s. In Nashville, it was the hottest year ever logged. Figures at the state capital stretch back 150 years.
“Not only is it getting warmer in the Appalachian Highlands,” said Dr. Andrew Joyner, Tennessee’s official climatologist and a member of the Department of Geosciences, “we are also seeing an increase in extreme weather, from flash flooding to rapid-onset droughts.”
What does all this mean, especially in Appalachia? Experts at East Tennessee State University take a look, giving three takeaways for a warming Appalachia:
1. Trouble for native plants
If temperatures continue to rise, as a range of scientists anticipate, the rich biodiversity of the Southern Appalachian mountains could look different.
“One of the biggest impacts locally will be the unique habitats of the higher elevations that have a climate more similar to southeastern Canada than the rest of the Southeast U.S.,” said William Tollefson, the assistant state climatologist and a lecturer in Geosciences at ETSU. “The plants there especially are at risk if temperatures continue to warm as they are already confined to the highest elevation cool zones.”
A bevy of beloved plants and trees rely on historic weather patterns.
The Fraser fir, native to the region and usually found at high elevations, has adapted to cooler, moist conditions. It’s a similar story for rhododendrons, famous for their beauty and quantity.
Rising temperatures could threaten both.
2. Heat-related illness
Toasty weather also increases the chance of a range of medical issues.
Some are unpleasant but mild, including heat cramps and heat rash. Others are far more serious, including heat stroke and heat exhaustion, often leading to hospitalization and sometimes death.
“A lot of our construction and farm workers and others who work outside during the summer may be at increased risk for heat-health related issues going forward,” Joyner said.
According to the CDC, 2023 saw high levels of heat-related illness, something the agency has tracked since 2018.
3. More AC in the mountains
In 2024, plenty of Americans have central air conditioning.
But that isn’t always true in the highest elevations of the Appalachian Highlands, where it simply isn’t needed for portions of the year.
As temperatures creep up, that reality could change, increasing demand in the region.
“While most people here now have central AC, it will become more necessary going forward even for those in the higher elevations, where it’s cooler than Johnson City,” Joyner added.
As weather grows more unstable, ETSU plays key role in mitigation efforts
ETSU plays a critical role in ensuring that plans exist throughout the Volunteer State when natural disasters occur.
In late 2023, the state of Tennessee announced that the 2023 Tennessee State Hazard Mitigation Plan had received approval from the Federal Emergency Management Agency.
“As we saw in the projections from the newest state mitigation plan, which ETSU played a leading role in crafting, one of the bigger concerns with our changing weather is the increase in precipitation and especially the chance for increased extreme precipitation events and flash flooding,” said Joyner.
A look at historical climate data shows a trend toward increasing precipitation, especially in Northeast Tennessee, usually the driest part of the state, as well as a growing chance for what forecasters term “flash droughts.”
“This may seem counter-intuitive, but precipitation may increase, overall, with more extreme precipitation days, followed by longer periods between rainfall,” he said. “This could lead to more flash droughts, especially in the summer and fall months, which could have major agricultural implications. At the same time, we have seen a modest reduction in long-term drought periods.”
